1. Field of the Invention
This invention relates to an output jack for an electric guitar such as an electric acoustic guitar, and more particularly, to an output jack installed at a body of the electric guitar and adapted to receive a plug connected to one end of a cable which couples an output of the electric guitar to an external electrical circuit device.
2. Description of the Prior Art
An electrical signal obtained by a pickup device for picking-up vibrations of guitar strings is transmitted to an external amplifier and a loudspeaker via an output jack installed at a guitar body. The jack is electrically connected to the pickup device and the external amplifier with respective lead wires.
FIG. 1 shows a conventional jack installation structure in an electric acoustic guitar. In FIG. 1, a body 1 comprises a sound board 2, a back board 3, and a side board 4, which construct a sound box, and has a sound hole 8 at the central portion of the sound board 2. To an outer surface of the sound board 2 is secured a tail-piece 5 by a bonding agent. A bridge 6 for being saddled by six strings 10, and six pins 7 for fixing ends of the strings 10 are disposed on the tail-piece 5. To a head side of the body 1 is securely fixed a neck 9, and the strings 10 are tigntened between the pins 7 and tuning keys disposed at a head portion of the neck (not shown). Under the bridge 6 or at an appropriate portion of the tail-piece 5 is mounted a pickup device having a piezo-electric element and a pair of terminals attached opposite surfaces of the element (not shown). Musical sound of electrical signal which is converted from mechanical vibrations of the strings 10 is transmitted to an amplifier device disposed on a surface of the side board 4 in the sound box of the body 1. An amplified musical sound signal from the amplifier device 12 is transmitted, via lead wires 15, to a jack 14 installed at a tail portion 1A of the body 1. A block 13 is adapted to reinforce the tail portion 1A. Accordingly, the amplified musical sound signal is transmitted to an external electric circuit device and a loudspeaker, via the lead wires 15, the jack 14, a plug 16 to be connected to the jack 14, and lead wires for electrically coupling the plug 16 to the external device. An opening portion of the jack 14 has a hook portion which functions as an end pin for receiving a strap 17.
The prior art structure as described above, however, has following drawbacks. As the connections between the lead wires 15 and terminals 19 of the jack 14 is made by using solder, it is easily possible that open-circuiting at the connections and short-circuiting between the terminals 19 will be developed, and a solder bonding work is troublesome. Furthermore, it is necessary to utilize an electromagnetic shielding member for preventing electromagnetic induction at the connection portion between the lead wires 15 and the terminals 19 of the jack 14. A nut 20 for fixing the jack 14 in FIG. 1, accordingly, has a special shape which shields the terminals 19. However, the nut 20 must be fastened in the sound box of the body 1, so that the fastening work is also troublesome, and it is difficult to fasten the nut 20 securely, and a special instrument for fastening the nut 20 is required.